Dual MEAN WELL LRS-350 PSU

thingiverse

A set of 3D printable parts to compactly combine two LRS-350 PSUs into a single unit with optional voltage and current displays. I created this device to consolidate ten individual power bricks for each compute node in my home lab into just one power supply, allowing me to clean up the wiring, reclaim space, and free up several outlets on the power distribution system in my rack. It's also an excuse to sharpen some of my Fusion 360 skills! In theory, swapping out multiple small SMPS with a larger one (with equivalent total load) should be more efficient, but I don't have the time or tools to confirm this. You can also make similar claims about the quality of the output power, but I haven't checked the ripple on this supply compared to the multiple supplies it replaces. The compute nodes in my rack are a mix of 12V devices and 19V Intel NUCs. Since I couldn't find a 19V rated power supply, I used a 24V version that can be 'dialed down' to only 20V, which is well within the 19V ± 10% that the Intel NUCs require. I use a segment of cheap DIN rail and some terminal blocks to tidy everything up. ## Additional Hardware: - [2x DC Voltmeter&Ammeter](https://www.amazon.com/gp/product/B072BY4XZ7/): Optional, but suggested so you can keep an eye on current demands. You don't need to print `meter-panel.stl` if you omit the meters. You can also use your slicer to 'cut' the second meter cutout if you decide to use only one meter. - [2x MEAN WELL LRS-350](https://www.amazon.com/gp/product/B07VTLJS18/): Any two will fit. I designed this specifically for two different voltages, but that's not a requirement. - [1x IEC socket + Rocker Switch w/ Fuse](https://www.amazon.com/gp/product/B07KS2TQ45/): A simple way to BYO power cord and still have a kill switch and over-current protection. - [M4 Screws](https://www.mcmaster.com/91274A115): I used a combination of 8, 10, 12 mm screws for this design, but you can use only 8MM screws. You'll get 'better' attachment to the PSU modules with 10mm, but 8 will work. - DIN rail / blocks. Any 'UK2.5B' style DIN terminal block will work with any 'NS35-S' style rail. ## Additional CAD Components: To help with the design, I used several components from [grabcad.com](https://grabcad.com/library). The components used are: - [DIN Rail](https://grabcad.com/library/parametric-din-rail-1): Thanks to [Dennis Yilmaz](https://grabcad.com/dennis.yilmaz) for this one. - [Generic DIN Terminal Block](https://grabcad.com/library/terminal-block-5): Thanks to [Narendran K](https://grabcad.com/narendran.k) for this one. This model does not *precisely* match the rail blocks that I used, but it was useful for general size/alignment purposes. - [MeanWell LRS model](https://grabcad.com/library/mean-well-lrs-350-24-1): Thanks to [Chris](https://grabcad.com/chris.1010) for this one. The models don't _quite_ match the PSUs that I got, but the model was perfect for screws and height measurements. - [IEC Socket Model](https://grabcad.com/library/power-inlet-iec-320-c14-1): Thanks to [Sisul Galog](https://grabcad.com/sisul.galog) for this one. The models don't _quite_ match the screw holes on the actual part that I ordered from Amazon, but otherwise was a perfect fit. ## License and Source: I have included the Fusion 360 file should you want to make any modifications. It's not the cleanest timeline, but the names should be clear enough to figure out how things are put together. I didn't have an overarching design in mind when I started, so that's part of why the timeline is messy. You **do _not_ have my permission to use the source file or any rendered artifacts (stl/3mf files) for any commercial purpose**. Please let me know if you do make any modifications and please share the update Fusion 360 file so we can all learn how you did the mod.